This research program is directed toward obtaining a better understanding of the basic mechanisms of speech production. This is to be accomplished through direct studies of speech physiology and speech acoustics as they relate to human communication and by the indirect methods of speech synthesis. The methods to be used for direct observation of articulatory processes include cineradiography, three- dimensional radiography and fiberoptic laryngoscopy. Measurements of air flow through the mouth and intraoral pressure will aslo be made. Based on data obtained in these investigations, models of the processes will be formulated and simulated on a digital computer. The computer simulated models will be used as a basis for testing the state of knowledge of the processes involved and, if found satisfactory, will provide a procedure for producing synthetic speech. The synthesis procedure will then provide a working model of certain aspects of speech production which can itself be used for further investigations into the mechanisms of both normal and pathological aspects of speech production.